Update TEST_MAPPING am: 16d59a6498

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/fnv/+/1806079

Change-Id: I29ba7b3cd5e2eebb70f1471f87ec415b8771f91b
diff --git a/TEST_MAPPING b/TEST_MAPPING
index 30d2306..82241e1 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -1,4 +1,4 @@
-// Generated by cargo2android.py for tests in Android.bp
+// Generated by update_crate_tests.py for tests that depend on this crate.
 {
   "presubmit": [
     {